TGF-β1 regulates the lncRNA transcriptome of ovarian granulosa cells in a transcription activity-dependent manner

Objectives Transforming growth factor beta 1 (TGF-beta 1), an essential cytokine belongs to TGF-beta superfamily, is crucial for female fertility. Increasing evidence show that long noncoding RNAs (lncRNAs) influence the state of granulosa cells (GCs). This study aimed to detect the effects of TGF-beta 1 on the lncRNA transcriptome, and investigate whether lncRNAs mediate the functions of TGF-beta 1 in GCs. Material and Methods RNA-seq and bioinformatics analyses were performed to identify and characterize the differentially expressed lncRNAs (DElncRNAs). The regulatory mechanism of TGF-beta 1 to lncRNA transcriptome was analyzed by chromatin immunoprecipitation. The effects of lncRNAs on the antiapoptotic and proproliferative functions of TGF-beta 1 were examined by morphological analysis, fluorescence-activated cell sorting, Cell Counting Kit-8, and Western blot. Results A total of 72 DElncRNAs highly sensitive to TGF-beta 1 were identified with the criteria of |log(2)(fold chage)| >= 3 and false discovery rate < 0.05. Functional assessment showed that DElncRNAs were enriched in TGF-beta, nuclear factor kappa B, p53, and Hippo pathways which are crucial for the normal state and function of GCs. Importantly, SMAD4 is essential for the regulation of TGF-beta 1 to lncRNA transcriptome. In vitro studies confirmed that TGF-beta 1 induced TEX14-IT1 transcription in a SMAD4-dependent manner, and TEX14-IT1 mediated the antiapoptotic and proproliferative effects of TGF-beta 1 in GCs. Conclusions Our findings demonstrate that TGF-beta 1 alters lncRNA transcriptome in a SMAD4-dependent manner, and highlight that lncRNAs mediate the functions of TGF-beta 1 in GCs, which contribute to a better understanding of the epigenetic regulation of female fertility.